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921.
Ferritin was purified 33,000-fold from the plasma of patients with idiopathic hemochromatosis. The plasma ferritin was labeled with 131I and injected into 2 normal men. Clearance was found to be relatively slow, with 50% 131I-ferritin remaining in the plasma at 27-30 hr. The fraction of plasma ferritin that bound to concanavalin-A was found to be cleared more slowly than the nonbinding fraction. These findings confirm our previous suggestion that glycosylation is a major factor prolonging the survival of ferritin in the plasma, but differ from the results of earlier studies in experimental animals and preterm infants, which indicated very rapid plasma ferritin turnover. 相似文献
922.
The benzylic methylene protons in a large number of benzyloxycarbonyl α-aminoisobutyric acid (Z-Aib) containing peptides, show chemical shift nonequivalence. The magnitude of the geminal nonequivalence is correlated with the involvement of the urethane carbonyl group, in an intramolecular hydrogen bond. Studies of the model compounds Z-Aib-Aib-Ala-NHMe, and Z-Aib-Aib-Aib-Pro-OMe clearly establish the presence of intramolecular hydrogen bonds, involving the urethane CO group. In both compounds marked anisochrony of the benzylic methylene protons is demonstrated. In Z-Aib-Aib-Pro-OMe, where a 4 → 1 hydrogen bonded β-turn is not possible, the benzylic -CH2- protons appear as a singlet in CDCl3 and have a very small chemical shift difference in (CD3)2SO. The observation of such nonequivalence is of value in establishing whether the amino terminal Aib-Pro β-turn is retained in large peptide fragments of alamethicin. 相似文献
923.
Watt AC; Ackerman LV; Windham JP; Shetty PC; Burke MW; Flynn MJ; Grodinsky C; Fine G; Wilderman SJ 《Radiology》1986,159(1):39-42
To evaluate its potential for differentiating benign from malignant breast lesions, digital subtraction angiography of the breast (DSAB) was performed in 23 women with mammographic evidence of disease, and the results were compared with surgical biopsy findings. The DSAB technique employed breast immobilization with modest compression and bolus injection; following the injection of contrast material, 30-40 sequential subtraction images were obtained over a 5-minute interval. The average technical settings were 50 k Vp and 10 mAs, resulting in an estimated radiation dose to the breast of 0.05 mrad (0.5 mu Gy) per exposure. DSAB consistently demonstrated retention of contrast material and abnormal vasculature in malignant lesions but not in benign lesions. In the 22 breast lesions for which there was histopathologic correlation, DSAB correctly categorized eight of nine malignant and 11 of 13 benign lesions. Although this series is small, the initial results of DSAB suggest its potential for differentiating benign from malignant lesions. 相似文献
924.
Fourteen children who experienced acute, profound central nervous system hypoxia secondary to near drowning, aspiration, or respiratory arrest underwent CT examination. During the first week after the episode, the most frequent finding was a loss of gray-white matter differentiation. Other findings included effacement of sulci and cisterns, focal areas of edema in the cerebral cortex or basal ganglia, and hemorrhagic infarctions of the basal ganglia. Subsequent CT scans obtained from two weeks to five months after the hypoxic episode showed progression of cerebral loss from cortical infarction with gyral hemorrhage and enhancement to global parenchymal atrophy. The prognosis is poor in these patients: seven children experienced severe neurologic deficits and seven died. 相似文献
925.
926.
Adrenoleukodystrophy: correlating MR imaging with CT 总被引:6,自引:0,他引:6
Kumar AJ; Rosenbaum AE; Naidu S; Wener L; Citrin CM; Lindenberg R; Kim WS; Zinreich SJ; Molliver ME; Mayberg HS 《Radiology》1987,165(2):497-504
The effect on the brain of the sex-linked recessive form of adrenoleukodystrophy was studied in 40 boys, 4-18 years old. All underwent computed tomography (CT) scanning; six underwent magnetic resonance (MR) imaging. MR showed a high sensitivity in demonstrating white matter disease. Auditory pathway disease was characterized as involvement of the lateral lemniscus and medial geniculate body, and visual pathway disease was characterized by lateral geniculate body, Meyer loop, and optic radiation involvement. Contrast-enhanced CT still proved to have a greater capacity (at this time) to show the active, advancing form of the disease and concomitant calcifications. This large CT series also demonstrated the broad and variable expressions of adrenoleukodystrophy, which allowed the unification of previously described atypical forms of the disease. 相似文献
927.
Ten percent of children with biliary atresia have an associated complex of anomalies, including polysplenia, azygous continuation of the inferior vena cava, preduodenal portal vein, hepatic arterial anomalies, and bilaterally bilobed lungs. These abnormalities will not be detected if the preoperative workup is limited to hepatobiliary nuclear scanning. Ultrasonography is important in the preoperative evaluation of patients suspected of having biliary atresia. It is important to identify the associated abnormalities preoperatively because they have an impact on the initial portoenterostomy and may preclude subsequent orthotopic liver transplantation. 相似文献
928.
Miller DL; Doppman JL; Chang R; Simmons JT; O'Leary TJ; Norton JA; Spiegel AM; Marx SJ; Aurbach GD 《Radiology》1987,165(3):601-607
Angiographic ablation of parathyroid adenomas with ionic contrast material was performed in 24 patients with persistent hyperparathyroidism who had undergone at least one prior unsuccessful surgical resection; 23 had mediastinal adenomas. The success rate was 83% at 1 month after ablation and 71% at both 5 and 9 years. Ablation was successful in 85% of the patients in whom the catheter could be wedged into the artery feeding the adenoma. Long-term success was achieved in 89% of the patients in whom contrast enhancement persisted in the adenoma on computed tomographic scans obtained 24 hours later. Acute complications were seen only in patients with glands supplied by the inferior or superior thyroid arteries. Long-term complications were limited to permanent hypocalcemia, present in 8% of patients. Even if unsuccessful for ablation, the procedure may provide localization and does not preclude surgical resection. It is recommended for most patients with persistent hyperparathyroidism and mediastinal adenomas, especially adenomas supplied by the internal thoracic artery. 相似文献
929.
930.
BACKGROUND: Patients with multiple or uncommon red cell (RBC) alloantibodies require special efforts in the blood bank. This study investigated whether such persons had other immune-related conditions that might help to explain or predict their propensity for RBC antibody formation. STUDY DESIGN AND METHODS: Charts were retrospectively reviewed of 29 men and 83 women with multiple (> or = 3) RBC antibodies of potential clinical significance, uncommon RBC antibodies (anti-e, - Kpb, -Jkb, -Fyb, -S, -U, -Yta, -Dib, -Ata), or both. The clinical features in 43 women with multiple antibodies were compared to those in two equal-sized control cohorts of women matched for transfusion- related diagnoses, but having either one RBC antibody or none. RESULTS: Women with uncommon RBC antibodies had a 33-percent (18/54) prevalence of autoimmune disease. Twenty-eight percent of the 43 women with multiple antibodies had autoimmune disease, compared to 14 percent of women in the cohort with one RBC antibody (p = 0.09) and 7 percent of those in the cohort without RBC antibodies (p = 0.01). Only one of the 29 men had autoimmune disease. CONCLUSION: Autoimmune disease is a common underlying factor in women who make multiple or uncommon RBC alloantibodies of potential clinical significance. 相似文献